//https://www.cnblogs.com/ajaemp/p/12880847.html

const  sheet2blob =(sheet, sheetName)=> {
    sheetName = sheetName || 'sheet1'
    var workbook = {
      SheetNames: [sheetName],
      Sheets: {}
    }
    workbook.Sheets[sheetName] = sheet
    // 生成excel的配置项
    var wopts = {
      bookType: 'xlsx', // 要生成的文件类型
      bookSST: false, // 是否生成Shared String Table，官方解释是，如果开启生成速度会下降，但在低版本IOS设备上有更好的兼容性
      type: 'binary'
    }
    var wbout = XLSX.write(workbook, wopts)
    var blob = new Blob([s2ab(wbout)], { type: 'application/octet-stream' })
    // 字符串转ArrayBuffer
    function s2ab(s) {
      var buf = new ArrayBuffer(s.length)
      var view = new Uint8Array(buf)
      for (var i = 0; i !== s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF
      return buf
    }
    return blob
  }
  
  /**
   * 通用的打开下载对话框方法，没有测试过具体兼容性
   * @param url 下载地址，也可以是一个blob对象，必选
   * @param saveName 保存文件名，可选
   */
   const  openDownloadDialog=(url, saveName) => {
    if (typeof url === 'object' && url instanceof Blob) {
      url = URL.createObjectURL(url) // 创建blob地址
    }
    var aLink = document.createElement('a')
    aLink.href = url
    aLink.download = saveName || '' // HTML5新增的属性，指定保存文件名，可以不要后缀，注意，file:///模式下不会生效
    var event
    if (window.MouseEvent) event = new MouseEvent('click')
    else {
      event = document.createEvent('MouseEvents')
      event.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null)
    }
    aLink.dispatchEvent(event)
  }
  